Neuroendocrine Modulation of Metabolic Effects in Overweight Adolescents
This study will examine hormonal differences in ghrelin and growth hormone in obese and normal weight adolescents and their relationship to body composition and insulin resistance. The study will also investigate the effect of the macronutrient composition of a meal on postprandial ghrelin levels and whether ghrelin responses will predict the degree of hunger and caloric intake at a subsequent meal.
|Study Design:||Observational Model: Case Control
Time Perspective: Cross-Sectional
|Official Title:||Neuroendocrine Modulation of Metabolic Effects in Overweight Adolescents|
- Peak Growth Hormone (GH) on the GH Stimulation Test [ Time Frame: Baseline ] [ Designated as safety issue: No ]Peak growth hormone (GH) on the GH stimulation test is a measure of the adequacy of GH secretion.
- Visceral Adipose Tissue [ Time Frame: Baseline ] [ Designated as safety issue: No ]Visceral adipose tissue was measured using magnetic resonance imaging at the level of the fourth lumbar vertebra (L4)
Biospecimen Retention: Samples Without DNA
Serum and urine collected
|Study Start Date:||May 2005|
|Study Completion Date:||June 2007|
|Primary Completion Date:||June 2007 (Final data collection date for primary outcome measure)|
The inclusion criteria will be girls 12-18 years of age. According to the Centers for Disease Control and Prevention, the definition of obesity is a BMI higher than the 95th percentile for age and sex, and that of overweight is a BMI between the 85th and 95th percentiles. Cases will be defined as having a body mass index (BMI) greater than the 95th percentile for age according to the 2000 Centers for Disease Control and Prevention growth charts.
Obesity is an epidemic that is striking people at younger ages than ever before. Obesity is associated with changes in the secretory patterns of several hormones including ghrelin, growth hormone (GH), and insulin, which have not been examined in the adolescent age group. Ghrelin, a primarily gastric hormone, increases appetite and is a GH secretagogue. This study will compare the alteration in secretion of ghrelin and GH in overweight and normal weight adolescent girls through frequent blood sampling and GH stimulation testing with growth hormone releasing hormone and arginine. The relationship between these hormones and insulin resistance, measured by 1H-nuclear magnetic resonance spectroscopy, and body composition, measured by dual energy x-ray absorptiometry and magnetic resonance imaging, will be investigated. This study will also determine the postprandial ghrelin response to test meals that vary by the type of predominant macronutrient, which may predict the degree of hunger and amount of intake at a subsequent meal. Understanding obesity-related changes in ghrelin and GH and their relationship to body composition, insulin resistance, and appetite will help in the development of strategies to reduce complications of obesity.
|United States, Massachusetts|
|Massachusetts General Hospital|
|Boston, Massachusetts, United States, 02114|
|Principal Investigator:||Anne Klibanski, MD||Massachusetts General Hospital|